An interior insulation system with moisture control

ABSTRACT

An interior insulation system with moisture control for an exterior building wall has a first insulation element adapted for abutting the interior surface of the external wall; a second insulation element abutting said first insulation element; a vapour barrier covering the interior surface of the second insulation element; and a support structure below the first and second insulation elements and supporting said first and second insulation elements The support structure has a gutter profile having a cavity with an upper opening and at least one ventilation opening, and a third insulation element is provided in at least a portion of said cavity.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is the U.S. national stage of PCT/EP2019/067656 filedJul. 2, 2019, which claims priority of European patent application18184166.9 filed Jul. 18, 2018, both of which are hereby incorporated byreference in their entirety.

FIELD OF THE INVENTION

The present invention relates to an interior insulation system withmoisture control for an exterior building wall, said system comprising afirst mineral wool insulation element adapted for abutting the interiorsurface of the external wall; a second mineral wool insulation elementabutting said first insulation element; a vapour barrier covering theinterior surface of the second insulation element; a support structurebelow the first and second insulation elements and supporting said firstand second insulation elements.

BACKGROUND OF THE INVENTION

Such interior insulation systems are also known as internal wallinsulation, inner or insulated dry lining and are fitted to the innersurface of an external building wall and are mainly designed tothermally insulate, respectively to avoid heat loss.

From WO2006/014858 such an exterior wall insulating system is known.

In some types of buildings, it is required or advantageous that theexterior walls of the building are insulated to improve the interiorclimate in the building and to save energy. In particular in relation toold buildings, it is often not possible to provide a new facade withinsulation on the exterior side of the building. Instead an interiorinsulation system is provided. However, having the insulation on theinside (the warm side) of the exterior wall can lead to watercondensation inside the insulation layer, which in turn means that theinsulation system must be able to absorb such moisture and prevent thegenerated moisture from damaging the interior building structures, suchas wooden floors or the like.

The moisture may occur from different sources. Water may penetratethrough small cracks in the exterior wall, such as a masonry wall. Watermay diffuse through an imperfect vapour barrier and the internallyfitted insulation and condensate on the inside of the cold wall. Toaddress this, in WO2006/014858 there is incorporated a wicking media inthe insulation product to transport the condensate away from theinterface between the insulating product and the exterior wall and downto the lower part of the insulation system. The condensate will beremoved to a more interior location where it can then evaporate into theinterior room of the building, due to the higher temperature in theinterior room.

The downside of this solution is that it does not provide a water buffermeaning that the water has to evaporate as fast back to the room as itcome in. If this is not possible it might lead to that the water willenter other cavities in the construction and cause damages such asgrowth of mould and fungus in the construction, which is particularlyharmful for the wooden structures.

Moreover, the lower part of the insulation system is not insulated andwill act as a thermal bridge. If the temperature in this lower part ofthe insulation system is not sufficiently high, there is a risk that thewater rather than evaporate will be soaking the floor or lowerconstruction parts and thereby increasing the risk of causing damage tothe building construction.

SUMMARY OF THE INVENTION

Accordingly, it is an object by the present invention to provide aninterior insulation system for a building where condensate water can betransported or guided and retained in a reservoir without the risk ofsoaking the floor or lower construction parts.

This object is achieved by an interior insulation system of theinitially mentioned kind, wherein the support structure comprises agutter profile having a cavity with an upper opening and at least oneventilation opening, and wherein a third mineral wool insulation elementis provided in at least a portion of said cavity.

According to the invention it is found advantageous that by providing agutter profile a tray structure is provided which can accommodate anysurplus liquid condensate, since the water vapour absorbed in the firstmineral wool insulation can be transported via the upper opening andinto the gutter profile. Hereby, any condensed water is stored andprevented from entering into the construction parts of the building. Thewater vapour or condensed water can also be confined in the thirdmineral wool insulation element inside the profile and evaporate throughthe ventilation opening(s) into the interior room of the building.

Thus, by a system according to the invention, it is advantageouslyachieved that condensed water can be stored in the gutter profile andthe insulation material therein so that a delayed release back into theroom of the water in evaporated form can be achieved.

By the invention, the function of the “moisture control” is able tohandle condensed water and provides a water buffer in the gutterprofile. The third mineral wool element in that respect confines thewater inside the gutter profile so that the water in the form of vapourcan evaporate later on from the cavity in the gutter profile.

Moreover, by providing a third mineral wool insulation element in thecavity of the gutter profile, the thermal conductivity of the lowerprofile structure and any unwanted thermal bridging is reduced.

Preferably, an inner wall cover, such as a gypsum board, is provided onthe vapour barrier on the interior surface of the second insulationelement. Hereby, vapour is prevented from diffusing from the interior ofthe building into the insulation.

In a preferred embodiment, at least the first and the third mineral woolinsulation elements are made of hydrophilic mineral wool fibrousmaterial. Hereby, the water transport capabilities of the mineral woolinsulation material are increased. To further increase the waterabsorption of the elements, at least one mineral wool element maycomprise a wetting agent.

In an advantageous embodiment, the hydrophilic mineral wool insulationelements comprise an anti-microbial substance, such as Benzalkoniumchloride. Hereby, the mineral wool is provided with an anti-fungitreatment so that any build-up of mould on the cold inner surface of theexterior wall is prevented.

In preferred embodiments, the density of the first and/or second mineralwool insulation elements is 20-120 kg/m³, preferably 30-100 kg/m³, morepreferably 40-80 kg/m³. They provide for the thermal performance of thesystem.

Advantageously, a third mineral wool insulation element has a density,which is higher than the density of the first and second mineral woolinsulation elements, and said density of the third mineral woolinsulation element is from 150-250 kg/m³, preferably approx. 200 kg/m³.Hereby, the third mineral wool element can carry the first and secondmineral wool elements as well as the gypsum board without beingcompressed, respectively ensuring that the gutter profile doesn'tdeflect under the load of the construction.

The gutter profile preferably comprises an upright first wall portionadapted for abutting the inner side of the exterior wall, asubstantially horizontal base portion (perpendicular to said first wallportion), a second innermost upright wall portion for receiving amounting of a floor panel or the like, and one or more insulationsupport portions, and wherein the cavity is defined by said first andsecond wall portions, said base portion and one or more insulationsupport portions. Hereby, a light-weight profile can be provided, whichis simple and inexpensive to manufacture. Preferably, in the gutterprofile, the insulation support portions comprise an upwards facingfirst support surface for the second insulation element and an upwardsfacing second support surface for accommodating the inner wall cover.

In the currently preferred embodiment, the portion of the cavity of thegutter profile underneath the second support surface is void.Furthermore, said second support surface is provided with a plurality ofventilation openings in at least a portion of said support surface. Thesecond support surface is preferably extending a width larger than thewidth of the inner wall cover leaving a gap between said inner wallcover and a floor panel above the second support surface, and whereinthe ventilation openings are provided at least in said gap portion ofthe second surface.

To facilitate easy installation, a U-shaped profile is preferablymounted on the upwards facing first support surface for receiving thesecond insulation element.

In order to achieve a compact insulation system, it is advantageous thatthe upper opening of the gutter profile is arranged so that the firstinsulation element is supported directly by the third insulationelement.

Preferably the gutter profile is a metal profile, preferably aluminium,and in particular, the gutter profile is preferably made of a sheetmetal, which is bent into shape. Hereby, the profile can be producedfrom a thin metal sheet, such as 1 mm thick aluminium profile, whichensures a high thermal conductivity through the profile that will heatup the deck construction and reduce the risk of mould, which isadvantageous when the deck construction is made of wood. If the deck ismade of inorganic material, such as concrete, the gutter profile canadvantageously be made of plastic.

In the insulation system according to the invention, the supportstructure preferably comprises both a lowermost support member and anuppermost support member for holding the insulation elements in place,wherein the lowermost member is the gutter profile. Hereby, theinsulation system according to the invention may be used in accordancewith the basic principle of well-known structures for partition walls,comprising horizontal base and ceiling U-profiles and verticalC-profiles. Said base or bottom U-profile forming the uppermost supportmember of the support structure.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following the invention is described in more detail withreference to the accompanying drawings in which:

FIG. 1 is a schematic cross-sectional side view of an interiorinsulation system with moisture control according to an embodiment ofthe invention;

FIG. 2 is a front view of same, where the insulation elements are partlycovered by an inner wall cover;

FIG. 3 is a schematic cross-sectional view of the gutter profileaccording to the invention; and

FIG. 4 is a diagram showing the performance of an interior insulationsystem according to the invention compared to a traditional interiorinsulation system.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In FIG. 1 an embodiment of the interior insulation system according tothe invention is shown. On the inside of an exterior building wall 1,the insulation system is installed on the floor 12 of a wood deck 11. InFIG. 1 the lowermost section of the insulation system installed on thewood deck is shown, and also the top section of an insulation systeminstalled underneath the wood deck 11 and at a lower storey is shown.

As shown in FIG. 1, a gutter profile 5 is provided on the top of thefloor panels abutting the inner surface of the outer wall 1. On top ofthe gutter profile 5, a first mineral wool insulation element 2 isprovided covering the inner surface of the exterior wall 1. A secondmineral wool insulation element 3 is provided next to the firstinsulation element 2. The second insulation element 3 is accommodated ina U-shaped bottom profile 14 provided on top of the gutter profile 5. Onthe inside of the second insulation element 3 a vapour barrier 4 isprovided, which is liquid and gas impermeable and extends downwardcovering not only the inner surface of the second insulation element 3but also a portion of the gutter profile 5 as shown in FIG. 1. On theinterior facing side of the insulation and inside the vapour barrier 4 agypsum plaster board 7 is provided as inner wall cover. On the innermostportion of the gutter profile 5 a skirting board 6 may be mounted asshown in FIG. 1. Between the skirting board 6 and the inner wall cover 7a small gap 10 is provided so that moisture accumulating in the cavity58 of the gutter profile 5 may evaporate through ventilation openings 57in the gutter profile 5 (see FIG. 3) and via the gap 10 into theinterior room of the building.

In the bottom of FIG. 1, it is shown the top mounting system 13 forholding the top portion of the insulation system according to anembodiment the invention to the lower side of the deck 11. An L-shapedprofile 16 is provided in the corner between the inner surface of theexterior wall 1 and the wood deck 11. An inverted U-shaped profile 15 isprovided for holding the second insulation element 3. Hereby, a slot foraccommodating the top edge portion of the first insulation element 2 isprovided between the vertical portion of the L-profile 16 and theexterior facing side of the inverted U-shaped profile 15. Similarly, inthe inverted U-shaped profile 15 there is also a slot for accommodatingthe top of the second insulation element 3.

In FIG. 2 the interior insulation system is shown seen from the insidepartly installed. To the left of the figure, the inner wall cover 7 andthe skirting board 6 are also mounted, whereas in the centre and theright side of the figure, the gutter profile 5 and the U-shaped profile14 on top of the gutter profile 5 are visible. As also shown, theinsulation system will comprise vertical frame profiles 30, liketraditional C-profiles extending between the top profile system 13 andthe bottom U-shaped profile 14 of the insulation system for holding theinsulation elements 3 in place and providing the structural strength ofthe system.

With reference to FIG. 3, the gutter profile 5 is shown with its varioussections. The gutter profile 5 is preferably made from a metal sheetwhich is bent into the desired shape. In an alternative embodiment, thegutter profile is made of plastic material.

In the shown embodiment, the profile 5 has an upright first wall portion51 adapted for abutting the inner side of the exterior wall 1, asubstantially horizontal base portion 52 (perpendicular to said firstwall portion), a second innermost upright wall portion 53 for receivinga mounting of a skirting board 6 or the like (see FIG. 2), a horizontalsupport portion 54 succeeded by an upwards facing portion 56 and aninsulation support portion 55. The cavity 58 of the gutter profile 5 isdefined by said first and second wall portions 51, 53, said base portion52 and the insulation support portion 55 and the step portions 54 and56. An upper opening 59 is hereby also provided such that the firstinsulation element 2 can rest on the third insulation element 8 providedinside the cavity 58 (see FIG. 1).

At least the first and third mineral wool insulation elements 2, 8 areadvantageously adapted to absorb water and hence may be denoted ashydrophilic mineral wool fibrous elements. To achieve this effect, it isfound advantageous that the mineral wool elements are made with awetting agent to provide the mineral wool with increased hydrophilicproperties. Other options however are available to achievehydrophilicity as will appear from the below.

Mineral Wool

The mineral wool for the mineral wool fibrous elements are made ofMan-made vitreous fibres (MMVF) which can be glass fibres, ceramicfibres, basalt fibres, slag wool, stone wool and others, but are usuallystone wool fibres, bounded with a binder. Stone wool generally has acontent of iron oxide at least 3% by weight and content of alkali earthmetals such as calcium oxide and magnesium oxide from 10 to 40% byweight along with the other usual oxide constituents of MMVF. These aresilica; alumina; alkali metals such as sodium oxide and potassium oxidewhich are usually present in low amounts; and can also include titaniaand other minor oxides. Fibre diameter is often in the range of 2 to 10μm, preferably 3 to 5 μm. The MMVF material is in the form of a coherentmass. That is, the MMVF material is generally a coherent matrix of MMVF,which has been produced as such and formed into mineral wool elementsfor the interior insulation system according to the present invention.

Hydrophilicity

Normal the MMVF material for mineral wool insulation contains oil formaking the products hydrophobic and prevents them from absorbingmoisture. The MMVF material for the first and third mineral wool fibrouselements of the interior insulation system is however, manufacturedwithout adding of oil to make the elements less hydrophobic, and mayeven be hydrophilic so that it attracts water. The MMVF material for theelements can be hydrophilic due to the binder system used, the binderitself may be hydrophilic and/or a wetting agent is used.

The hydrophilicity of a sample of MMVF can be measured by determiningthe sinking time of a sample. A sample of MMVF material havingdimensions of 100×100×65 mm is required for determining the sinkingtime. A container with a minimum size of 200×200×200 mm is filled withwater. The sinking time is the time from when the sample first contactsthe water surface to the time when the test specimen is completelysubmerged. The sample is placed in contact with the water in such a waythat a cross-section of 100×100 mm first touches the water. The samplewill then need to sink a distance of just over 65 mm in order to becompletely submerged. The faster the sample sinks, the more hydrophilicthe sample is. The MMVF material is considered hydrophilic if thesinking time is less than 120 seconds.

Preferably, the sinking time is less than 60 seconds. In practice, theMMVF material may have a sinking time of a few seconds, such as lessthan 10 seconds.

When the binder is hydrophobic, a wetting agent is additionally includedin the MMVF material in order to ensure that the material ishydrophilic. A wetting agent will increase the amount of water that theMMVF material can absorb. The use of a wetting agent in combination witha hydrophobic binder results in a hydrophilic MMVF material.

The wetting agent used may be any of the wetting agents known for use inMMVF material that are used for growth substrates. For instance, it maybe a non-ionic wetting agent such as Triton X-100 or Rewopal. Otherwetting agents may be used, for instance anionic wetting agents such aslinear alkyl benzene sulphonate or sodium lauryl ether sulphate (alsocalled SLES). An example of an anionic SLES is Disponil FES27A suppliedby BASF.

In a preferred embodiment, the wetting agent is a Benzalkonium chloride,which is commercially available under the trademark name Rodalon® byBrenntag Nordic A/S. Said wetting agent is particularly beneficial as italso acts as an anti-microbial substance which will be apparent from thedescription further down.

The binder of the MMVF material can be hydrophilic. The hydrophilicbinder does not require the use of a wetting agent. A wetting agent cannevertheless be used to increase the hydrophilicity of a hydrophilicbinder in a similar manner to its action in combination with ahydrophobic binder. This means that the MMVF material will absorb waterfaster than if the wetting agent is not present. Any hydrophilic binderknown per se can be used.

Binder

The binder may be any binders known for use as binders for coherent MMVFproducts. The binder may be an aldehyde based resin such as phenolformaldehyde resin (PF), phenol urea formaldehyde resin (PUF), ureaformaldehyde resin (UF), melamine formaldehyde resin (MF), melamine ureaformaldehyde resin (MUF), melamine phenol formaldehyde resin (MPF), andmelamine urea phenol formaldehyde resin (MUPF). This type of binder canbe economically produced for use as a binder in many applicationsincluding mineral wool elements of the type used in the presentinvention.

The binder may be a formaldehyde-free aqueous binder compositioncomprising: a binder component (A) obtainable by reacting at least onealkanolamine with at least one carboxylic anhydride and, optionally,treating the reaction product with a base; and a binder component (B)which comprises at least one carbohydrate, as disclosed inWO2004/007615. Binders of this type are hydrophilic.

Further formaldehyde-free binder compositions such as those comprising:

-   a) a sugar component, and-   b) a reaction product of a polycarboxylic acid component and an    alkanolamine component,    wherein the binder composition prior to curing contains at least 42%    by weight of the sugar component based on the total weight (Dry    matter) of the binder components may be used in the present    invention, preferably in combination with a wetting agent.

The binder may be a furan binder, as disclosed in WO97/07664, whichlends its hydrophilic properties to the material. The use of furan resinallows for not adding a wetting agent. Binders of this type may be usedin the hydrophilic mineral wool elements in the present invention.

The mineral wool elements are made by melting the raw materials in largecupola furnaces at a temperature of about 1500° C. The melt is directedonto a series of fast rotating wheels spinning (if stone wool) andformed into rock fibres with an average diameter of about 2 to 10microns. A binding agent is added and, for hydrophilic products, anadditional wetting agent can be introduced (see above). The wool is thencured in special curing ovens.

The mineral wool insulation elements may further be provided with ananti-microbial substance, such as Benzalkonium chloride. Benzalkoniumchloride, which is commercially available under the trademark nameRodalon® by Brenntag Nordic A/S, is advantageous in the context of thepresent invention due to its anti-fungi properties and therebypreventing any occurrence of mould on the wall on which the insulationsystem is mounted.

In FIG. 4, the graph shows the water uptake and release over time fortwo types of interior insulation. The measurements are done inlaboratory with controlled climatic conditions.

By the term or function “moisture control” used in this disclosure ismeant the control of the water uptake and release over time for aninterior insulation, which function is guaranteed using a gutter profilecomprising said third mineral wool insulation element according to thepresent invention.

The upper curve (blue) is the reference and represents a traditionalinterior insulation system. Here an existing wall is insulated with 100mm hydrophobic mineral wool with a density of around 50 kg/m³ followedby a 0.2 mm plastic vapour barrier and a gypsum board. The gypsum boardis mounted on 38×56 mm timber battens. The vapour barrier is sealedaround the perimeter in order to make it as tight as possible.

The second curve (red) represents the solution according to the presentinvention with 50 mm hydrophilic mineral wool with a density of around40 kg/m³ followed by 50 mm hydrophobic mineral wool with a density ofaround 50 kg/m³ followed by a 0.2 mm plastic vapour barrier of the sametype and with identical properties than the one tested with thetraditional system, and a gypsum board. The gypsum board is mounted on45×40 mm thin metal C-profiles. The vapour barrier is sealed to theceiling and the walls and to the gutter profile at floor in order tomake it as tight as possible.

The size of each of the tested wall elements is 40×60 cm; the materialof the existing wall is chosen of 100 mm light concrete.

In the measurements the temperature is controlled at the outside of thewall and the temperature and humidity is controlled on the inside of thewall.

The weight increase was measured on a digital weight once a week.

In the first 4 month hot, very humid inside conditions (25° C. and 80%relative humidity (RH)) and cold outside conditions (−15° C.) wassimulated. Here both constructions absorbed moisture.

In the next 4 month hot moderate humid inside conditions (25° C. and 40%RH) and cold outside conditions (−15° C.) was simulated. Here thereference solution had a moderate evaporation while the solutionaccording to the present invention had a much faster evaporation.

In the next month hot relative humid inside conditions (23° C. and 60%RH) and cold outside conditions (−15° C.) was simulated. Here bothconstructions absorbed a little moisture.

In the next month hot relative low humid inside conditions (23° C. and50% RH) and warm outside conditions (23° C.) was simulated. Here bothconstructions evaporated a little moisture.

After 10 month the amount of water in the solution according to thepresent invention was more than 10 times lower than in the referencesolution. This reduces the risk of growth mould and fungus very much.

When doing interior insulation measures in a building with a wooden deckthere is a risk that because the wall become colder it can lead to mouldin the wood construction. In a preferred embodiment of the presentinvention, this risk is minimized by using heat conductive metalprofiles, such as aluminium profiles, that heat up the area where thewood deck touches the wall, respectively where it is supported in theexternal wall structure.

To quantify this effect simulations of the temperatures have beenperformed on an exterior building wall with a wood deck construction asshown in FIG. 1. The 2D calculation tool Therm 7.0 developed by BerkeleyNational Laboratory have been used.

The temperature in the middle of the wood deck was calculated with andwithout the metal profiles. The inside temperature was set to 20° C. andthe outside temperature was set to −12° C.

Without the metal profiles the wood temperature was calculated at 1.9°C.; with the metal profiles the wood temperature was calculated to 5.5°C.; meaning a raise of 3.6° C. This temperature difference of 3.6° C.substantially reduces the risk of mould.

Above the invention is described with reference to some preferredembodiment. However, it is realised by the invention that otherembodiments or variants of the above described examples of an interiorinsulation system according to the invention may be provided withoutdeparting from the accompanying claims.

1. An interior insulation system with moisture control for an exteriorbuilding wall, said system comprising: a first mineral wool insulationelement adapted for abutting an interior surface of the external wall; asecond mineral wool insulation element abutting said first insulationelement; a vapour barrier covering an interior surface of the secondinsulation element; and a support structure below the first and secondinsulation elements and supporting said first and second insulationelements; wherein the support structure comprises a gutter profilehaving a cavity with an upper opening and at least one ventilationopening, and wherein a third mineral wool insulation element is providedin at least a portion of said cavity.
 2. The interior insulation systemaccording to claim 1, wherein an inner wall cover, such as a gypsumboard, is provided on the vapour barrier on the interior surface of thesecond insulation element.
 3. The interior insulation system accordingto claim 1, wherein at least the first and the third insulation elementsare made of hydrophilic mineral wool fibrous material.
 4. The interiorinsulation system according to claim 3, wherein the hydrophilic mineralwool insulation elements comprise a wetting agent.
 5. The interiorinsulation system according to claim 3, wherein the hydrophilic mineralwool insulation elements comprise an anti-microbial substance, such asBenzalkonium chloride.
 6. The interior insulation system according toclaim 1, wherein the third mineral wool insulation element has adensity, which is higher than the density of the first and secondmineral wool insulation elements, and said density of the third mineralwool insulation element is from 150 to 250 kg/m³, preferably approx. 200kg/m³.
 7. The interior insulation system according to claim 1, whereinthe gutter profile comprises an upright first wall portion adapted forabutting the inner side of the exterior wall, a substantially horizontalbase portion perpendicular to said first wall portion, a secondinnermost upright wall portion for receiving a mounting of a skirtingboard or the like, and one or more insulation support portions, andwherein the cavity is defined by said first and second wall portions,said base portion and one or more insulation support portions.
 8. Theinterior insulation system according to claim 7, wherein in the gutterprofile, the insulation support portions comprise an upwards facingfirst support surface for the second insulation element and an upwardsfacing second support surface for accommodating the inner wall cover. 9.The interior insulation system according to claim 8, wherein said secondsupport surface is provided with a plurality of ventilation openings inat least a portion of said support surface.
 10. The interior insulationsystem according to claim 9, wherein said second support surface isextending a width larger than the width of the inner wall cover leavinga gap between said inner wall cover and a floor panel above the secondsupport surface, and wherein the ventilation openings are provided atleast in said gap portion of the second surface.
 11. The interiorinsulation system according to claim 8, wherein a U-shaped profile ismounted on the upwards facing first support surface for receiving thesecond insulation element.
 12. The interior insulation system accordingto claim 1, wherein the upper opening of the gutter profile is arrangedso that the first insulation element is supported directly by the thirdinsulation element.
 13. The interior insulation system according toclaim 1, wherein the gutter profile is a metal profile, preferablyaluminium.
 14. The interior insulation system according to claim 1,wherein the gutter profile is made of a sheet metal, which is bent intoshape.
 15. The interior insulation system according to claim 1, whereinthe gutter profile is made of plastic.